Constructing Crystalline Covalent Organic Frameworks from Chiral Building Blocks

• Published in: Journal of the American Chemical Society Vol. 138; no. 36; pp. 11489 - 11492
• Main Authors: Xu, Hai-Sen, Ding, San-Yuan, An, Wan-Kai, Wu, Han, Wang, Wei
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 14-09-2016
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/jacs.6b07516

Covalent organic frameworks (COFs) represent a new type of crystalline porous materials that are covalently assembled from organic building blocks. Construction of functional COFs is, however, a difficult task because it has to meet simultaneously the requirements for crystallinity and functionality. We report herein a facile strategy for the direct construction of chiral-functionalized COFs from chiral building blocks. The key design is to use the rigid scaffold 4,4′-(1H-benzo­[d]­imidazole-4,7-diyl)­dianiline (2) for attaching a variety of chiral moieties. As a first example, the chiral pyrrolidine-embedded building block (S)-4,4′-(2-(pyrrolidin-2-yl)-1H-benzo­[d]­imidazole-4,7-diyl)­dianiline (3) was accordingly synthesized and applied for the successful construction of two chiral COFs, LZU-72 and LZU-76. Our experimental results further showed that these chiral COFs are structurally robust and highly active as heterogeneous organocatalysts.